fix(02): revise plans based on checker feedback

.planning/phases/02-audio-synthesis-engine/02-01-PLAN.md

@@ -127,7 +127,7 @@ type WindowSnapshot struct {
 
 6. Verify CGo build works by running `CGO_ENABLED=1 go build ./...` — should succeed with no errors.
 
-NOTE: Do NOT add go-audio/wav. Per research recommendation, skip the WAV intermediate and write PCM bytes directly to LameWriter. This eliminates a dependency and avoids the io.WriteSeeker complication.
+NOTE: Skipping go-audio/wav — per CONTEXT.md Claude's Discretion grant for "WAV intermediate format usage," the WAV intermediate is unnecessary. Phase 2 research (Pitfall 4) confirmed go-audio/wav requires io.WriteSeeker which bytes.Buffer does not satisfy. Writing interleaved int16 PCM bytes directly to go-lame's LameWriter.Write() is simpler and eliminates one dependency. CLAUDE.md updated to reflect this decision.
   </action>
   <verify>
     <automated>go version && gcc --version && ffprobe -version && grep "go-lame" go.mod && CGO_ENABLED=1 go build ./...</automated>

.planning/phases/02-audio-synthesis-engine/02-03-PLAN.md

@@ -25,7 +25,7 @@ must_haves:
       provides: "Integration test with ffprobe validation and zero-packet guard test"
       contains: "TestMP3Valid"
     - path: "cmd/netsynth/main.go"
-      provides: "-o flag wiring with timestamp default"
+      provides: "-o flag wiring with timestamp default, snapshot slice accumulator stub"
       contains: "outputPath"
   key_links:
     - from: "encode/mp3.go"
@@ -225,7 +225,7 @@ Write tests FIRST, using `os.CreateTemp` for output files and `exec.Command("ffp
 </task>
 
 <task type="auto">
-  <name>Task 2: Wire -o output flag into CLI</name>
+  <name>Task 2: Wire -o output flag and snapshot accumulator stub into CLI</name>
   <files>cmd/netsynth/main.go</files>
   <read_first>
     - cmd/netsynth/main.go (current Cobra flag setup, run function)
@@ -255,9 +255,16 @@ Add the `-o` / `--output` flag to main.go. Per D-15: defaults to `netsynth-<time
 
 4. Add `"time"` to the imports.
 
-5. Add a comment in the snapshot consumption loop marking where Phase 3 will wire synthesis:
+5. Add a snapshot slice accumulator alongside the existing snapshot consumption loop, and a TODO for Phase 3 wiring. Replace the current `for snap := range snapshots` block to also collect snapshots into a slice:
    ```go
-   // TODO(phase-3): Pass snapshots to encode.RunSynthesis(snapshots, outputPath)
+   // Accumulate snapshots for synthesis (Phase 3 will pass to encode.RunSynthesis)
+   var collectedSnapshots []classify.WindowSnapshot
+   for snap := range snapshots {
+       collectedSnapshots = append(collectedSnapshots, snap)
+       aggregate.AccumulateTotals(totals, snap)
+   }
+
+   // TODO(phase-3): Pass collectedSnapshots to encode.RunSynthesis(collectedSnapshots, outputPath)
    ```
 
 Do NOT import the encode package yet — Phase 3 handles that. The flag must be functional (parseable, shows in --help) even though the synthesis pipeline isn't wired.
@@ -271,10 +278,12 @@ Do NOT import the encode package yet — Phase 3 handles that. The flag must be
     - cmd/netsynth/main.go contains `netsynth-%s.mp3`
     - cmd/netsynth/main.go contains `time.Now().Format("20060102-150405")`
     - cmd/netsynth/main.go imports `"time"`
+    - cmd/netsynth/main.go contains `var collectedSnapshots []classify.WindowSnapshot`
+    - cmd/netsynth/main.go contains `TODO(phase-3)` referencing `encode.RunSynthesis`
     - `go build ./cmd/netsynth/` exits 0
     - `go run ./cmd/netsynth/ --help` output contains `-o, --output`
   </acceptance_criteria>
-  <done>The -o/--output flag is registered in Cobra, defaults to netsynth-<timestamp>.mp3, visible in --help. Build succeeds. Phase 3 will wire it to RunSynthesis.</done>
+  <done>The -o/--output flag is registered in Cobra, defaults to netsynth-<timestamp>.mp3, visible in --help. Snapshot slice accumulator stub is in place for Phase 3 wiring. Build succeeds.</done>
 </task>
 
 </tasks>
@@ -284,12 +293,14 @@ Do NOT import the encode package yet — Phase 3 handles that. The flag must be
 - `ffprobe` validates the test-generated MP3 (within encode test)
 - `go run ./cmd/netsynth/ --help` shows `-o, --output` flag
 - `grep "no packets captured" encode/mp3.go` confirms zero-packet error message
+- `grep "collectedSnapshots" cmd/netsynth/main.go` confirms snapshot accumulator stub
 </verification>
 
 <success_criteria>
 - encode/mp3.go produces valid MP3 files from synthetic WindowSnapshots (validated by ffprobe)
 - Zero-packet guard prevents file creation and returns descriptive error (OUT-03)
 - -o flag registered in CLI with timestamp default (OUT-01)
+- Snapshot slice accumulator ready for Phase 3 wiring
 - Full test suite passes: `CGO_ENABLED=1 go test ./...`
 - Complete Phase 2 audio pipeline validated end-to-end against synthetic data
 </success_criteria>

.planning/phases/02-audio-synthesis-engine/02-VALIDATION.md

@@ -0,0 +1,97 @@
+---
+phase: 2
+slug: audio-synthesis-engine
+status: draft
+nyquist_compliant: true
+wave_0_complete: true
+tdd_model: co-creation
+created: 2026-03-26
+---
+
+# Phase 2 — Validation Strategy
+
+> Per-phase validation contract for feedback sampling during execution.
+
+---
+
+## Test Infrastructure
+
+| Property | Value |
+|----------|-------|
+| **Framework** | go test (stdlib) |
+| **Config file** | none — existing Go test infrastructure |
+| **Quick run command** | `go test ./synth/... ./encode/...` |
+| **Full suite command** | `go test ./...` |
+| **Estimated runtime** | ~5 seconds |
+
+---
+
+## TDD Model
+
+This phase uses **co-creation TDD**: tests are written within the same task as the implementation, following RED-GREEN-REFACTOR within each task. All TDD tasks are marked with `tdd="true"` in their plan XML. Test files are created as part of the task, not as a separate Wave 0 plan.
+
+This is explicitly chosen over pre-existing stub TDD because:
+1. Each task's `<behavior>` block defines expected test cases before implementation begins
+2. The executor writes tests FIRST (RED), then implementation (GREEN) within the same task
+3. No test file exists before the task starts — the task creates both test and implementation
+
+Wave 0 requirements are limited to environment/tooling setup (gcc, ffprobe, go-lame dependency), handled by Plan 01 Task 1.
+
+---
+
+## Sampling Rate
+
+- **After every task commit:** Run `go test ./synth/... ./encode/...`
+- **After every plan wave:** Run `go test ./...`
+- **Before `/gsd:verify-work`:** Full suite must be green
+- **Max feedback latency:** 5 seconds
+
+---
+
+## Per-Task Verification Map
+
+| Task ID | Plan | Wave | Requirement | Test Type | Automated Command | TDD | Status |
+|---------|------|------|-------------|-----------|-------------------|-----|--------|
+| 02-01-01 | 01 | 1 | SYNTH-01 | setup | `go version && gcc --version && ffprobe -version && grep "go-lame" go.mod && CGO_ENABLED=1 go build ./...` | n/a | ⬜ pending |
+| 02-01-02 | 01 | 1 | SYNTH-01, SYNTH-02 | unit | `cd /home/dev/workspace/yoloyolo && go test ./synth/... -v -count=1` | co-creation | ⬜ pending |
+| 02-02-01 | 02 | 2 | SYNTH-03 | unit | `cd /home/dev/workspace/yoloyolo && go test ./synth/... -run "TestPan\|TestStereo\|TestClamp" -v -count=1` | co-creation | ⬜ pending |
+| 02-02-02 | 02 | 2 | SYNTH-03 | unit | `cd /home/dev/workspace/yoloyolo && go test ./synth/... -run "TestNewBank\|TestRenderWindow\|TestMixerNoClip\|TestStereoPan\|TestMultipleWindows" -v -count=1` | co-creation | ⬜ pending |
+| 02-03-01 | 03 | 3 | OUT-02, OUT-03 | integration | `cd /home/dev/workspace/yoloyolo && CGO_ENABLED=1 go test ./encode/... -v -count=1` | co-creation | ⬜ pending |
+| 02-03-02 | 03 | 3 | OUT-01 | build | `cd /home/dev/workspace/yoloyolo && go build -o /dev/null ./cmd/netsynth/ && go run ./cmd/netsynth/ --help 2>&1 \| grep -q "\-o.*output" && echo "OK"` | n/a | ⬜ pending |
+
+*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*
+
+---
+
+## Wave 0 Requirements
+
+- [x] `gcc` — C compiler required for go-lame CGo compilation (Plan 01, Task 1)
+- [x] `ffprobe` — MP3 validation in acceptance tests (Plan 01, Task 1)
+- [x] `go get github.com/sjzar/go-lame@v0.0.9` — MP3 encoding dependency (Plan 01, Task 1)
+- [x] `go-audio/wav` — **Skipped.** Per CONTEXT.md Claude's Discretion grant; write PCM bytes directly to LameWriter (CLAUDE.md updated).
+
+*Test stubs are co-created with implementation in each TDD task (see TDD Model section above).*
+
+---
+
+## Manual-Only Verifications
+
+| Behavior | Requirement | Why Manual | Test Instructions |
+|----------|-------------|------------|-------------------|
+| Perceptually distinct drone tones per traffic class | SYNTH-01 | Subjective audio quality | Play output MP3, verify each class sounds distinct |
+| Amplitude rises/falls audibly with traffic volume | SYNTH-02 | Subjective perception | Listen for volume changes across windows with varying traffic |
+| Stereo panning creates spatial separation | SYNTH-03 | Subjective audio quality | Listen with headphones, verify bass center and highs spread |
+
+---
+
+## Validation Sign-Off
+
+- [x] All tasks have `<automated>` verify commands matching plan blocks
+- [x] Sampling continuity: no 3 consecutive tasks without automated verify (all tasks have automated verify)
+- [x] Wave 0 covers environment/tooling setup (Plan 01, Task 1)
+- [x] Co-creation TDD model documented; test expectations defined in `<behavior>` blocks
+- [x] No watch-mode flags
+- [x] Feedback latency < 5s
+- [x] `nyquist_compliant: true` set in frontmatter
+
+**Approval:** ready

CLAUDE.md

@@ -30,7 +30,7 @@ A Go CLI tool that captures live network traffic on an interface, clusters and c
 | Library | Version | Purpose | When to Use |
 |---------|---------|---------|-------------|
 | `github.com/muesli/kmeans` | v0.3.1 | K-means clustering for unrecognized traffic patterns | Use to auto-cluster packets that don't match known protocol rules. Feed feature vectors: [port, protocol_num, packet_size_bin, direction]. Last release July 2022 but mathematically stable; the algorithm doesn't change. Alternatively, implement a simple incremental classifier directly (see Architecture notes below). |
-| `github.com/go-audio/wav` | latest | WAV file I/O as intermediate format | Use to write synthesized PCM as WAV before MP3 encoding pass. "Battle tested" per maintainer. Simplifies the PCM → encoder pipeline: synthesize float64 samples → write WAV → re-read as PCM → LAME encode. |
+| `github.com/go-audio/wav` | latest | WAV file I/O as intermediate format | **Optional.** Originally recommended for PCM intermediate buffering, but Phase 2 research found that go-audio/wav requires `io.WriteSeeker` (which `bytes.Buffer` does not satisfy) and adds unnecessary complexity. The simpler approach is writing interleaved int16 PCM bytes directly to go-lame's `LameWriter.Write()`. Skip unless a WAV debug output feature is needed. Decision made under CONTEXT.md Claude's Discretion grant for "WAV intermediate format usage." |
 | `golang.org/x/sys/unix` | stdlib | Raw socket / CAP_NET_RAW privilege checks | Use for detecting if the process has required privileges and for signaling (SIGINT for clean shutdown). Part of Go extended stdlib — no external version pinning needed. |
 ### Development Tools
 | Tool | Purpose | Notes |